Cholera is a bacterial infection of the gut. Most persons
infected with do not become ill. When illness does occur,
more than 90% of episodes are mild or moderate and are difficult
to distinguish from other types of travellers' diarrhoea.
Simple rehydration is the treatment for these cases. Cholera
can cause copious, painless, watery diarrhoea 'rice water
stools'; those who are malnourished or immuno-suppressed
are more likely to develop these symptoms.

Transmission

Cholera is acquired primarily by ingesting
contaminated water or food; person-to-person transmission is rare.
Raw or undercooked seafood from polluted water has also been associated
with outbreaks. The incubation period ranges from less than one
day to five days.

Occurrence

Occurs mainly in poor countries with
inadequate sanitation and lack of clean drinking water and in war
torn countries where the infrastructure may have broken down. Many
developing countries are affected particularly those in Africa
and Asia , and, to a lesser extent, those in central and south
America . Disease outbreaks tend to be associated with slum areas
or refugee camps where there is overcrowding, no safe disposal
of faeces and no access to clean water.

Risk for Travellers

Cholera is a disease associated with
slums and extreme poverty, it is unusual for travellers to take
water or food from these areas, the risk of disease is therefore
low and travellers are not considered to be at significant risk.

Risk Reduction

The risk of infection is reduced by
taking hygienic precautions with all food, drink and drinking-water
consumed when travelling.

Vaccination

Vaccination is not recommended for
most travellers due to the low risk but may be recommended for
those at particular risk including those working in slum areas,
refugee camps or hospitals in endemic areas. Those visiting friends
and family in areas reporting cholera cases, military personnel
in conflict zones and travellers visiting rural areas currently
or recently reporting an outbreak of cholera may also benefit from
vaccination.

Diphtheria causes a moderately sore throat with a greyish
membrane over the infected area. In severe cases the neck
tissue may become very swollen. In tropical countries the
infection may occur in skin ulcers. After 2-6 weeks, severe
muscle weakness develops, mainly affecting the muscles of
the head and neck. Inflammation of the heart muscle may cause
heart failure.

Transmission

Transmission is from person to person,
through close physical contact (particularly kissing, sharing bottles/glasses
etc) and / or droplet infection and is increased in overcrowded
and poor socioeconomic conditions. The incubation period is 1 to
9 days.

Occurrence

Diphtheria is found worldwide, although
it is not common in industrialized countries because of long-standing
public health vaccination programmes. Recently, large epidemics
have occurred in several east European countries. Diphtheria currently
mainly occurs in parts of eastern Europe, Russia and several other
states of the former Soviet Union , and parts of Africa and Asia
.

Risk for Travellers

Incompletely immunised travellers to
endemic areas may be at risk depending on activities.

Risk Reduction

The risk of infection can be reduced
by avoiding close contact with people in crowded and enclosed places.

Vaccination

All travellers should have had the
primary course of vaccination. Travellers to areas where Diphtheria
is still common should have had a booster in the last 10 years
particularly if they are likely to be in close (face to face) contact
with local populations.

This is a viral disease of the liver. Symptoms include fever,
chills, weakness, loss of appetite, nausea and abdominal
discomfort, followed within a few days by jaundice (yellowing
of the skin and eyes). Urine becomes dark and stools pale.
Many infections, particularly in children, are often without
specific symptoms. In others, jaundice may be severe and
prolonged

Transmission

Virus is acquired directly from the
infected person by the faecal - oral route or by close contact,
or by eating and drinking contaminated food and water. Food outbreaks
are often linked to raw or undercooked shellfish and raw vegetables.

Occurrence

Hepatitis A is found worldwide but
most common where sanitation conditions are poor and the safety
of drinking water and food preparation is not well controlled.

Risk for Travellers

Travellers from industrialized countries
are likely to be susceptible to infection. While people travelling
to rural areas of developing countries are at particularly high
risk of infection, in practice most cases occur among travellers
staying in resorts and good-quality hotels.

Risk Reduction

The risk of infection is reduced by
taking hygienic precautions with all food, drink and drinking-water
consumed when travelling.

Vaccination

Immunisation is usually advised for
those going to areas where the standards of food and water hygiene
are lower than the UK . People born and raised in developing countries,
and those born before 1945 in industrialized countries, have often
been infected in childhood and are likely to be immune. For such
individuals, it may be cost-effective to test for anti-HAV antibodies
so that unnecessary vaccination can be avoided. If time is short,
it is safe to receive hepatitis A vaccine.

Hepatitis B is viral infection affecting the liver usually
has an insidious onset of vague abdominal pain, nausea, vomiting
and loss of appetite which often progresses to jaundice (yellowing
of the skin and eyes). The urine is dark.

Recovery takes about 28 days but may sometimes be more prolonged.
Long lasting or chronic infection occurs in 0.5-20% of cases.
An estimated 15-25% of those with chronic infection can develop
cirrhosis or liver cancer.

Transmission

The virus is transmitted through contaminated
blood and blood related body fluids thus it may be acquired by
transfusion with infected blood, the use of unsterilised needles
and syringes (e.g. IV drug users and tattooists) and by unprotected
sexual intercourse. The incubation period is 2 weeks to 6
months.

Risk for Travellers

While only certain categories of traveller
are clearly at risk because of their planned activities, any traveller
may be involved in an accident or medical emergency that requires
surgery.

Risk Reduction

Adopt safe sexual practices and avoid
the use of any potentially contaminated instruments for injection
or other skin-piercing activities e.g. tattooing.

The vaccine should be considered for
virtually all travellers potentially involved in high risk activities
e.g. health care that entails direct exposure to human blood, and
/ or to areas with poor medical facilities where HIV is endemic
(particularly for repeat / long stay travellers). A course of three
vaccinations is required; the preferred schedule for maximum efficacy
being vaccination at 0, 1 and 6 months. However, an accelerated
course can be given for "long stay high risk" travellers but an
additional dose will be required 6-12 months later.

This is a viral disease which can cause a severe flu-like
illness with headache, neck stiffness, confusion and coma.
Most cases are asymptomatic; In those that do develop symptoms
of disease (approximately 1 in 200 infections become clinically
apparent), mortality may be greater than 30% and long-term
effects on the nervous system are common.

Transmission

JE is spread by night time biting,
rural area (Culex) mosquito which breeds in rice (paddy) fields
and mainly bites animals particularly pigs and some wild birds.
The incubation period is usually 5-15 days.

Occurrence

JE occurs in a number of countries
in Asia and occasionally in northern Queensland , Australia .

Risk for Travellers

The risk of infection with (JE) for
travellers to South-East Asia is low but varies with the season
(being higher during the monsoon), the type of accommodation and
the duration of exposure. Short stays in good hotels with limited
likelihood of mosquito bites result in very low levels of risk.
In contrast, campers in rural areas may be at high risk. No more
than one case per year is diagnosed in civilian travellers worldwide.

Risk Reduction

Avoid mosquito bites. As the mosquitoes
tend to feed outside rather than indoors any type of accommodation
offers protection. Avoid sleeping outdoors near large concentrations
of animals especially pigs.

Vaccination

Vaccination is only advised for those
going to risk areas for periods of a month or more. Travellers
who are thought to be at very high risk e.g. working near pig farms
/ paddy fields may be recommended this vaccination for shorter
stays.

Measles is a highly contagious infection which presents
with fever, red rash and runny nose. Common complications
include middle-ear infection and pneumonia.

Transmission

The measles virus is transmitted by
close contact with infected persons and / or airborne respiratory
droplet infection.

Occurrence

Measles occurs worldwide, although
it is rare in industrialised countries due to immunisation programmes.
Transmission increases during the late winter and early spring
in temperate climates, and after the rainy season in tropical climates.

Risk for Travellers

Measles is still common in many countries
and travel in densely populated areas may favour transmission.

Risk Reduction

The risk of infection can be reduced
by avoiding close contact with people in crowded and enclosed places.

Meningitis is the infection of the membrane lining of the
brain and spinal cord. Most infections do not cause clinical
disease; instead the infected person becomes a "carrier".
Symptoms have a sudden onset of intense fever with severe
headache, neck stiffness, photophobia and a blotchy rash
is common.

It can occur in epidemics, especially where large crowds
are gathered, as. The onset is usually sudden and progression
to coma is often rapid if treatment is not started.

Transmission

Transmission occurs through direct
person-to-person contact including inhalation of bacteria in droplets
coughed or sneezed into the air by infected persons or carriers.
In general susceptibility decreases with age, although there is
a small increase in risk in adolescents and young adults. The incubation
period is usually 3-4 days.

Occurrence

Sporadic cases are found world wide.
In temperate zones most cases occur in the winter. Localised outbreaks
occur in enclosed crowded spaces e.g. dormitories. In parts of
sub-Saharan Africa (meningitis belt) large outbreaks and epidemics
occur during the dry season (November-June).

Risk for Travellers

The risk is considered to be generally
low, however is increased for those in crowded conditions or who
take part in large population movements e.g. pilgrimages in the "meningitis
belt". Long-term travellers living in close contact with the indigenous
population in risk areas may be at greater risk of infection.

Localised out breaks in travellers normally occur in young
adults in camps / dormitories.

Risk Reduction

Avoid overcrowding in confined spaces
and close contact with local population.

Vaccination

Vaccination is not recommended for
most travellers unless the risk of exposure is considered to be
significant.

Pertussis (whooping cough) is a highly contagious acute
bacterial disease involving the respiratory tract. Although
pertussis can occur at any age, most serious cases and fatalities
are observed in early infancy and mainly in developing countries.

Polio is a viral infection of the gut the initial symptoms
of which are fever, headache, nausea and vomiting. The virus
then invades the blood stream and nervous system and may
result in permanent paralysis (this risk increases with age).

Transmission

Transmission is mainly via the faecal - oral
route although rare outbreaks caused by contaminated food or water
have occurred. The incubation period is 7-14 days.

Occurrence

Wild poliovirus transmission has ceased
in all industrialized countries and much of the developing world
however still occurs in non developed countries.

Risk for Travellers

Travellers to endemic areas are at
risk if they have not been fully immunised. Infected travellers
are also potent vectors for transmission and possible re-introduction
of the virus into polio-free zones now that worldwide eradication
is near.

Risk Reduction

The risk of infection is reduced by
taking hygienic precautions with all food, drink and drinking-water
consumed when travelling and by avoiding direct contact with polluted
recreational waters.

Vaccination

Travellers to endemic areas should
avoid overcrowded environments e.g. All travellers should be up
to date with vaccination against poliomyelitis. Any un-immunised
individuals intending to travel to such an area require a complete
course of vaccine.

Rabies is a viral disease primarily affecting animals but
humans can also be infected. The virus travels from the site
of entry (the bite or scratch) via the nerves to the brain
and spinal cord and eventually spreads to the salivary glands.
Symptoms start with itching and tingling at the site of the
healed bite and then rapidly progresses to include headache,
fever, spreading paralysis, confusion and aggression and
hydrophobia (fear of water).. Unfortunately, once symptoms
have developed, rabies is fatal.

Transmission

Rabies is usually transmitted by the
bite of an infected animal as the virus is present in the saliva.
Dog bites are by far the most common source of infection, particularly
in developing countries, however cats, bats, foxes, skunks, raccoons,
monkeys and many other animals can also be carriers. Animals may
be infectious for five days before they develop symptoms

A scratch to the skin, a lick on a fresh skin break or contact
of the infected saliva with intact mucous membranes may also
transmit rabies - all such "suspect contacts" should be treated
with caution.

It may take many weeks or months for symptoms to develop
although it is usually 2-8 weeks (but can in rare circumstances
be a short as 4 days)

Occurrence

Asia , Africa and South America report
more than 99% of the deaths. India alone reports 30,000 deaths
annually - and many cases may not be reported. The World Health
Organisation estimate there are 50,000 human deaths from rabies,
and more than 10 million people receive post exposure vaccination
each year. As rabies is not a notifiable disease in many countries,
this is regarded to be an underestimate.

Risk for Travellers

Travellers may be at risk if there
is contact with wild and domestic animals in rabies-endemic areas

Risk Reduction

Never approach or handle animals you
don't know, particularly if they are acting strangely.

Take care not to carry food when visiting temples where
monkeys are present. Monkeys can scratch as they try and
grab food from you.

Do not "adopt" or feed local / stray animals

If bitten by a potentially infected animal, or following
any suspect contact, immediately clean the wound with soap
and water and disinfectant (or 70% proof alcohol) and seek
medical assistance immediately: see the OHS advice leaflet "Rabies
Post-Exposure Treatment" for further information.

Vaccination

Pre-exposure immunisation against rabies
is recommended for long-stay travellers/residents, those who intend
to travel to rural and remote areas and those countries where modern
rabies vaccines are not available. In the event of a bite, your
body's responses could be quickly activated by booster doses of
vaccine.

The disease can almost always be prevented, even after exposure,
if vaccine is administered without delay. Travellers should
seek one of the modern vaccines however these can be difficult
to obtain abroad and if necessary, the British Embassy or
consulate should be contacted for a supply. Some countries
are using less effective locally produced vaccines that have
to be administered into the abdomen; these are best avoided
if possible.

This anaerobic bacterial infection produces a toxin which
circulates in the body to cause severe and painful muscular
contractions and spasms which often lead to death through
respiratory problems and exhaustion.

Transmission

Tetanus spores ( Clostridium tetani)
are present in soil and may be introduced into the body during
injury through a puncture wound, burn or trivial, unnoticed wounds.
The incubation period is 4-21 days, commonly about 10 days.

Occurrence

Tetani spores are found worldwide.

Risk for Travellers

Dirty wounds can become infected with
the tetanus spores anywhere in the world. Almost any form of injury,
from a simple laceration to a motor-vehicle accident, can expose
the individual to the spores.

Risk Reduction

The risk of infection can be reduced
by protecting the skin from direct contact with soil in places
where soil-transmitted infections are likely to be present e.g.
by using personal protective equipment (gloves etc) and appropriate
clothing.

Vaccination

All travellers should have had the
primary course of vaccination . Five doses of tetanus containing
vaccine are thought to provide life long cover. However, human
tetanus immunoglobulin (HTIG) may be given for high risk injuries
even if a full course of vaccine has been received in the past.
Travellers to areas with potentially poor medical facilities who
have not had a tetanus vaccine in the last 10 years should receive
a booster dose (even if they have already had 5 doses) as HTIG
may not be available.

Tick-borne encephalitis (TBE) is caused by members of the flavivirus family that can affect the central nervous system. It can cause inflammation of the brain (encephalitis), and non-specific flu-like illness, with fatigue, headache, malaise and fever.

Transmission

Transmission in humans is mainly through the bite of an infected tick with introduction of the virus via the tick saliva. It can also be less commonly transmitted by ingestion of unpasteurised milk from infected animals, especially goats.

Occurrence

Occurs in forested areas of Central, Eastern and Northern Europe, Russia Northern and Eastern areas of China, Japan and Siberia.

Risk for Travellers

Infections are mostly caused by leisure activity such as hiking and camping. The incidence peaks in spring and early summer, but can occur throughout the year for those travelling to rural endemic areas.

Risk Reduction

Cover up and wear long sleeves and trousers (tucked into socks) to prevent ticks entering the skin. Apply insect repellent to other exposed areas of the skin. Check the body for ticks regularly and if seen remove with a pair of tweezers or tick remover.

Vaccination

Immunisation is advisable those travelling to endemic areas, forestry workers and campers.
A course of three vaccinations is required at 0, 1 - 3 months and 5 - 12 months. The second dose can be accelerated by a two week interval for those travelling at short notice.

TB is a bacterial disease has a slow onset and presents
with general malaise, weakness and weight loss. Prolonged
close exposure may lead to infection but in 90% of cases,
the disease remains inactive or without symptoms for the
person's lifetime (latent TB). Approximately 10% of infected
individuals go on to develop active disease; those who are
immuno-suppressed or malnourished are more likely to be in
this group.

Occurrence

TB is found worldwide: the risk of
infection differs between countries.

Transmission

TB is usually transmitted by prolonged
close exposure to airborne droplets from a person with untreated
pulmonary (lung) or laryngeal TB.

TB may also be transmitted by unpasteurised milk and dairy
products from infected cows (Bovine TB).

Risk for Travellers

Low for most travellers. Long-term
travellers (over 3 months) to a country with a higher incidence
of tuberculosis than their own may have a risk of infection comparable
to that for local residents. As well as the duration of the visit,
living conditions are important in determining the risk of infection:
high-risk settings include health facilities, shelters for the
homeless, and prisons.

Risk Reduction

Travellers should avoid close contact
with known tuberculosis patients unless absolutely necessary (e.g.
field work)

Never drink unpasteurised milk. If in doubt, boil before
drinking.

Vaccination

BCG vaccination is recommended for
travellers who will be spending one month or more in a high risk
area and those planning close contact with the local population.
Those who have not received BCG immunisation should be offered
it (although the efficacy in adults is thought to be reduced) and
the vaccine should be administered at least 6 weeks before departure
to ensure a protective level of immunity.

Travellers who have already had the BCG vaccine do not require
Heaf testing or further vaccination, as this has never been
shown to provide additional protection.

This bacterial infection causes a prolonged feverish illness
with loss of appetite, lethargy and constipation. Constipation
is more common than diarrhoea in adults

Without treatment the illness can be fatal, with
perforation of the gut producing peritonitis or severe haemorrhage.
Paratyphoid fever is a similar but less severe variant. Around 2-5%
of those who contract typhoid fever become chronic carriers, as bacteria
persist in the biliary tract after symptoms have resolved.

Occurrence

Typhoid is found worldwide but occurs
most commonly in association with poor standards of hygiene in
food preparation and handling and where sanitary disposal of sewage
is lacking.

Transmission

Transmission is usually by consumption
of contaminated food or water (including milk and milk products.
). Contamination can occur from flies, sewage-polluted shellfish
beds, poor food hygiene etc. Raw fruit and vegetables are particularly
risky due to the practice of "night soil" fertilization (fertilization
with human sewage Occasionally direct faecal-oral transmission
may occur. The incubation period is from 1-3 weeks.

Risk for Travellers

Generally low risk for travellers,
except in parts of north and west Africa, in south Asia and in
Peru . Elsewhere, travellers are usually at risk only when exposed
to low standards of hygiene with respect to food handling, control
of drinking-water quality, and sewage disposal.

Risk Reduction

The risk of infection is reduced by
taking hygienic precautions with all food, drink and drinking-water
consumed when travelling

Vaccination

Typhoid vaccines are often recommended
for travellers going to areas where the standards of hygiene may
be unreliable however do not provide 100% protection and do not
protect against paratyphoid fever.

Yellow fever is a viral disease is characterised by a severe
flu-like illness in which a bleeding tendency and jaundice
may develop. Case fatality rates for non immune travellers
may be as high as 50%.

Transmission

Yellow fever is principally a disease
of jungle areas (monkeys are the principal animal reservoir) but
there are occasional small outbreaks in towns and cities. The disease
is transmitted by the bite of infected daytime biting mosquitoes.
Incubation period is 3-6 days.

Occurrence

The yellow fever virus is endemic in
some tropical areas of Africa and central and south America. The
number of epidemics has increased since the early 1980s. Other
countries are considered to be at risk of introduction of yellow
fever due to the presence of the vector and suitable primate hosts
(including Asia , where yellow fever has never been reported).

Risk for Travellers

Travellers are at risk in all areas
where yellow fever is endemic. The risk is greatest for visitors
who enter forest and jungle areas.

Risk Reduction

Avoid mosquito bites during the day
as well as at night.

Vaccination

Vaccination is highly effective in
conferring immunity and lasts 10 years. Vaccination is highly effective
in conferring immunity and lasts 10 years.

Vaccination is mandatory in some countries for visitors.
The initial vaccination must be given 10 days before travel
if the international certificate is to be valid, but re-vaccination
may be given at any time before expiry of the certificate
and is effective immediately.